Wind noise is a common problem for microphones. Wind present at the microphone inlet result in turbulence creating an audible noise. This is especially a problem when the microphone is used as part of a hearing aid system as the wind noise will lower speech intelligibility as well as induces stress on the user of the hearing aid device, due to the possible prolonged exposure of the wind noise on the user.
A possible solution to reduce wind noise is to use a porous material positioned in front of the microphone inlet for lowering the wind speed and thereby filtering out wind noise. To achieve an effective filtering effect, the porous material has to have a large size, thus increasing the total size of the microphone.
U.S. Pat. No. 3,154,171 discloses a noise suppressing filter using a porous material. However, the proposed filter has an undesirable directional sensitivity and increases the size of the microphone.
It remains a problem to provide a filter/audio recording device/hearing aid system capable of efficiently filtering out wind noise.